I just happened to test drive one the other day. It was a demonstrator with 4500 miles on it, so was marked way down. Nice heated leather seats and remote start and other frills this old lady might like.
I knew NOTHING about diesel cars. I did a ton of reading and found nothing but glowing reports about performance and reliability. Car and Driver got 43 mpg at 75 mph and in small towns, and a whopping 58 mpg at 55 mph. Sticker mileage is 27 - 46. No traditional cold starting, rattling, smell, fumes, gas problems.
A tiny bit of confusion of the 6 gear automatic at low speeds, and a tiny bit noisier from the outside, but not inside.

So why aren't people buying this car? It's a bit pricey? VW has all the diesel fans? I got a huge resistance to diesel from almost everyone I know on Facebook. They all think TRUCKS.

Price of gasoline is not high enough to force conversion to diesel in the U.S.

Even if we keep gas prices down (not what I call down, but what the heck), I predict that diesel cars will make inroads in the next few years. It just seems to make sense. We borrowed all the knowledge of Europeans on this and we are making good diesel engines.
I just don't drive enough anymore to make it worth it in my lifetime.